Initiation of growth hormone therapy in idiopathic short stature: do gender differences exist?

Background/Aims: Growth hormone (GH) registries indicate that boys receive preferential GH treatment for idiopathic short stature (ISS). The aim was to determine whether age, auxological parameters, pubertal status, and target height differ between genders at GH initiation. Methods: Review of the computerized files of the endocrine department of a tertiary pediatric medical center identified 184 patients who started GH therapy for ISS between 2003-2011. Data on auxologic parameters, predicted height, parental height, and pubertal status were collected and compared between boys and girls. Results: Boys accounted for a significantly higher percentage of the study group (65.8%, p<0.001). At onset of GH therapy, there were no significant differences between boys and girls in age (10.2 +/- 3.1 vs. 9.9 +/- 2.4 years), height-standard deviation score (SDS) (-2.64 +/- 0.5 vs. -2.79 +/- 0.5), body mass index-SDS[(-0.65 +/- 1.01) vs. (-0.80 +/- 1.13)], or pubertal status (66% vs. 63.5% prepubertal). Predicted height-SDS was significantly higher in boys (-1.95 +/- 1.05 vs. -2.56 +/- 0.73, p<0.001). Midparental height-SDS was similar in the two groups, as were paternal and maternal height. Conclusions: The similar age, height deficit, and pubertal status at onset of GH treatment in boys and girls suggests that gender differences do not exist. Male predominance may stem from family preferences to treat boys. Future studies are warranted to assess the psychosocial aspects in the decision to initiate therapy.